Shared channel structure, ARQ systems and methods

ABSTRACT

A forward link design is provided employing CDMA (code division multiple access) technologies in which time division multiplexing is employed between data and control information on the forward link to service multiple users per slot. Another forward link design employing CDMA (code division multiple access) technologies is provided in which code division multiplexing between data and control information is employed on the forward link to service multiple users per slot, which is preferably backwards compatible with legacy standards such as IS2000A. A reverse link design is also provided.

RELATED APPLICATIONS

[0001] This application claims the benefit of provisional application60/243,013 filed Oct. 24, 2000, provisional application 60/246,889 filedNov. 8, 2000, 60/250,734 filed Dec. 1, 2000, provisional application60/266,602 filed Feb. 5, 2001, and provisional application 60/277,951filed Mar. 23, 2001.

FIELD OF THE INVENTION

[0002] This invention relates to CDMA systems which provide both dataand voice functionality.

BACKGROUND OF THE INVENTION

[0003] Code Division Multiple Access (CDMA) is a cellular technologyoriginally standardized as IS-95, which competes with GSM technology fordominance in the cellular world. CDMA employs spread-spectrum technologywhich increases the capacity of cellular systems. CDMA was adopted bythe Telecommunications Industry Association (TIA) in 1993. Differentvariations now exist, with the original CDMA now known as cdmaOne. Forexample, there is now cdma2000 1×RTT and its variants like 1×EV-DO and1×EV-DV and 3×RTT Multi-Carrier (MC 3×). These basically refer tovariants of usage of a 1.25 MHz carrier channel. For example, MC 3× usesa 3.75 MHz carrier channel, By May 2001, there were 35 millionsubscribers on cdmaOne systems worldwide.

[0004] Third Generation efforts under ITU's IMT-2000 initiative havebeen motivated in large part by a need to increase the supported datarates over wireless channels. The demand for high rates has not been metby second generation systems since these systems have been defined anddesigned for only voice and low-rate data. Higher data rates requiremore bandwidth on the radio channel for transmission.

[0005] The cdma2000 standard is a 3rd Generation (3G) solution based onthe original IS-95 standard. Unlike some other 3G standards, cdma2000 isan evolution of an existing wireless standard. The cdma2000 standardsupports 3G services as defined by the International TelecommunicationsUnion (ITU) for IMT-2000. 3G networks will deliver wireless serviceswith better performance, greater cost-effectiveness and significantlymore content. Essentially, the goal is access to any service, anywhere,anytime from one wireless terminal i.e. true converged, mobile services.

[0006] Worldwide resources are currently being devoted to roll outthird-generation CDMA technology. The cdma2000 standard is one mode ofthe radio access “family” of air interfaces agreed upon by the OperatorsHarmonization Group for promoting and facilitating convergence of thirdgeneration (3G) networks. In other words, the cdma2000 standard is onesolution for wireless operators who want to take advantage of new marketdynamics created by mobility and the Internet. The cdma2000 standard isboth an air interface and a core network solution for delivering theservices that customers are demanding today.

[0007] The goal of the cdma2000 standard was to mitigate risks, protectinvestments and deliver significant performance boosts to operators asthey evolve their networks to offer 3G services. Networks based oncdma2000 are backward compatible to cdmaOne (IS-95) deployments,protecting operator investments in cdmaOne networks and providing simpleand cost-effective migration paths to the next generation. In addition,cdma2000 networks offer voice quality and voice capacity improvements,and support for high speed and multimedia data services.

[0008] The first phase of cdma2000—variously known as 1×RTT, 3G1×, orjust plain 1×—offers approximately twice the voice capacity of cdmaOne,average data rates of 144 kbps, backward compatibility with cdmaOnenetworks, and many other performance improvements. The cdma2000 1×RTTstandard can be implemented in existing spectrum or in new spectrumallocations. A cdma2000 1×RTT network will also introduce simultaneousvoice and data services, low latency data support and other performanceimprovements. The backward compatibility with cdmaOne provided bycdma2000 further ensures investment protection.

[0009] However, the cdma2000 standard is evolving to continually supportnew services in a standard 1.25 MHz carrier. In this regard, theevolution of CDMA2000 beyond 1×RTT is now termed CDMA2000 1×EV or 1×EVfor short. 1×EV is further divided into two stages: 1×EV-DO and 1×EV-DV.1×EV-DO stands for 1× Evolution Data only. 1×EV-DV stands for 1×Evolution Data and Voice. Both 1×EV evolution steps provide for advancedservices in cdma2000 using a standard 1.25 MHz carrier. The evolution ofcdma2000 will, therefore, continue to be backwards compatible withtoday's networks and forward compatible with each evolution option.

[0010] The 1×EV-DO standard is expected to be available for cdma2000operators sometime during 2002, and will provide for even higher datarates on 1× systems. Specifically, 1×EV-DO specifies a separate carrierfor data, and this carrier will be able to hand-off to a 1× carrier ifsimultaneous voice and data services are needed. By allocating aseparate carrier for data, operators will be able to deliver peak datatransmission rates in excess of 2 Mbps to their customers.

[0011] It is envisioned that 1×EV-DV solutions will be availableapproximately one and a half to two years after 1×EV-DO. A goal of1×EV-DV is to bring data and voice services for cdma2000 back into onecarrier. That is, a 1×EV-DV carrier should provide not only high speeddata and voice simultaneously, but should also be capable of deliveringreal-time packet services.

[0012] In summary, then, the cdma2000 1×RTT standard is optimized forvoice and provides basic packet data services up to 163.2 kbps. Thisstandard is currently being commercialized and will be in the marketvery soon if not already. The cdma2000 1×EV-DO standard is optimized fordata only and provides efficient data service up to 2 Mbps. Thisstandard is to be deployed after cdma2000 1×RTT. Finally, a proposedcdma2000 1×EV-DV standard is to be optimized for both data and voice.Providing simultaneous voice and data services, the goal of such astandard is to provide more spectrum efficiency. Therefore, in terms ofthe evolution path of the cdma2000 standards for wireless high-speeddata transmission, the cdma2000 1×RTT standard is currently progressingtowards a cdma2000 1×EV-DO standard which is, in turn, progressingtowards an optimized cdma2000 1×EV-DV standard.

[0013] In examining the migration path from the 1×RTT standard to1×EV-DO, those skilled in the art will appreciate that High Data Rate(HDR) technology served as the base technology for 1×EV-DO. Furthermore,the incorporation of the 1×RTT reverse link in 1×EV-DO achieved theobjectives of technology reuse as well as providing a cost-effectivesolution.

[0014] In a similar manner, a graceful evolution from 1×EV-DO to 1×EV-DVwill minimize re-investments and avoid fragmenting the industry. In thislight, 1×EV-DV should be backward compatible to the 1×RTT family ofstandards and products. In other words, customer and operatorinvestments in CDMA systems should be protected. There should be maximumreuse whenever possible and the 1×EV-DV standard should also considerpossible future evolutions such as packet voice.

[0015] In addition to the above, any 1×EV-DV proposal should meet theCDMA Development Group (CDG) and Operator's requirements. Specifically,1×EV-DV should support services with various QoS attributes,simultaneous voice and data on the same carrier, voice capacityenhancement, more spectrum efficiency in packet data transmission andscalability to 3× mode operations.

[0016] 1×EV-DO increases data capacity but does not allow for voice onthe same carrier and therefore does not change the voice capacity of thecdma2000 family. Voice traffic must continue to use 1×RTT. As of Oct.22, 2001 1×EV-DV proposals have integrated voice and data but voice ishandled in the same fashion as 1×RTT thus the voice capacity isunchanged.

SUMMARY OF THE INVENTION

[0017] A first broad aspect of the invention provides a method oftransmitting over a forward link in a CDMA (code division multipleaccess) communications system. The method involves transmitting forwardlink frames, each frame comprising a plurality of slots; for each slot,transmitting a forward shared channel, the forward shared channel beingadapted to have up to a predetermined maximum number of Walsh covers,and the forward shared channel being scheduled slot-wise to carry insome slots content for a single high-rate data user, in some slotscontent for a plurality of voice users (a voice user being voice orlow-rate data); and transmitting a user identification channel adaptedto allow users to determine which slots contain their content.

[0018] Preferably, the forward shared channel is further adapted to havescheduled in some slots content for a plurality of voice users and asingle high-rate data users.

[0019] In some embodiments, the user identification channel istransmitted in parallel with the shared channel using a different codespace.

[0020] Preferably, during each slot the forward shared channel isscheduled over a number of Walsh covers equal to the predeterminedmaximum number of Walsh covers minus a number of Walsh covers necessaryto accommodate legacy users being serviced during the slot.

[0021] The Walsh covers in some embodiments are 16-ary Walsh covers andin a given slot, one or more of the 16-ary Walsh covers is furthersub-divided for the plurality of voice users, with all remaining 16-aryWalsh covers of the forward shared channel being assigned to a shareddata channel which is made available to a single high-rate data user ata time.

[0022] Preferably, each slot has a 1.25 ms slot duration, with theshared data channel content for a given user may occupy multiplecontiguous slots.

[0023] Other, embodiments of the invention are defined in the appendedclaims 1 to 96.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will now be described in further detail by way ofexample with reference to the attached drawings in which:

[0025]FIG. 1A is a network schematic for a first embodiment of theinvention;

[0026]FIG. 1B is an example forward channel structure for use in theforward link of FIG. 1A;

[0027]FIG. 1C is an example forward voice traffic channel structure foruse with the forward channel structure of FIG. 1B;

[0028]FIG. 1D is an example forward data traffic channel structure foruse with the forward channel structure of FIG. 1B;

[0029]FIG. 1E is an example preamble channel structure for use with theforward channel structure of FIG. 1B;

[0030]FIG. 1F is an example power control and reverse activity channelstructure for use with the forward channel structure of FIG. 1B;

[0031]FIG. 1G is an example forward pilot channel structure for use withthe forward channel structure of FIG. 1B;

[0032]FIG. 2 is a first example of a forward link slot structureprovided by an embodiment of the invention;

[0033]FIG. 3 illustrates an example of how content might be scheduledusing the slot structure of FIG. 2;

[0034]FIG. 4 is a second example of a forward link slot structureprovided by an embodiment of the invention;

[0035]FIG. 5A is an example set of physical layer parameters for data onthe forward link;

[0036]FIG. 5B is an example set of physical layer parameters for voiceon the forward link for users having a high channel estimate;

[0037]FIG. 5C is an example set of physical layer parameters for voiceon the forward link for users having a medium channel estimate;

[0038]FIG. 5D is an example set of physical layer parameters for voiceon the forward link for users having a low channel estimate;

[0039]FIG. 6 is a channel summary for another CDMA forward linkstructure provided by an embodiment of the invention;

[0040]FIG. 7 is a slot structure of a forward link structure in whichthere are no legacy users;

[0041]FIG. 8 is a slot structure of a forward link structure in whichthere are legacy users;

[0042]FIG. 9 illustrates an example set of Walsh separation codes forthe forward link structures of FIGS. 7 and 8;

[0043]FIG. 10 is a block diagram of an example forward shared channelstructure for data and full rate voice;

[0044]FIG. 11 is a block diagram of an example forward shared channelstructure for non-full rate voice;

[0045]FIG. 12 is an example set of forward link shared channel voiceparameters;

[0046]FIGS. 13 and 14 are example sets of forward link shared channeldata parameters;

[0047]FIG. 15 is a block diagram of an example user identificationchannel structure;

[0048]FIG. 16 is a block diagram of an example supplementary pagingchannel structure;

[0049]FIG. 17A is a channel summary for CDMA reverse link structureprovided by an embodiment of the invention;

[0050]FIG. 17B is a block diagram of an example reverse CHESS channelstructure;

[0051]FIG. 18 is a block diagram of an example reverse data ARQ channelstructure;

[0052]FIG. 19 shows an example structure for the reverse pilot channel;

[0053]FIG. 20 is a reverse link timing diagram;

[0054]FIG. 21A is a block diagram showing reverse channel I and Qmapping;

[0055]FIG. 21B is a block diagram of the reverse advanced access/commoncontrol channel;

[0056]FIG. 21C is a block diagram of the reverse traffic/dedicatedcontrol channels;

[0057]FIG. 22 is an example lower rate set of reverse supplementarychannel coding and modulation parameters; and

[0058]FIG. 23 is an example higher rate set of reverse supplementarychannel coding and modulation parameters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059]FIG. 1A shows a system schematic of an example wireless system inwhich various embodiment of the invention may be employed. A basestation (BS) 160 is shown having three coverage area sectors 162, 164,166. The base station 160 forms part of a larger wireless access network(not shown). Different numbers of sectors may be employed. By way ofexample, shown are two wireless terminals (WT) 168, 170 in sector 162,although a sector may serve more than two wireless terminals. There is ashared forward link generally indicated by 172 used for transmissionsfrom the base station 160 to wireless terminals 168, 170. Each wirelessterminal also has a respective dedicated reverse link 174, 176. Both theforward link 172 and the reverse links 174, 176 employ CDMAfundamentals.

[0060] A first embodiment of the invention provides a forward linkdesign employing CDMA (code division multiple access) technologies inwhich time division multiplexing is employed between data and controlinformation on the forward link to service multiple users per slot. Thefirst embodiment will be described with reference to FIGS. 1 to 5.Preferably, this design may be employed as a forward link portion of a1×EV-DV solution. Another embodiment of the invention provides a forwardlink design employing CDMA (code division multiple access) technologiesin which code division multiplexing between data and control informationis employed on the forward link to service multiple users per slot,which is preferably backwards compatible with legacy standards such asIS2000A. This embodiment will be described below with reference to FIGS.6 to 16. Preferably, this design may be employed as a forward linkportion of a 1×EV-DV solution. Either of the forward link designs may beused in combination with a reverse link design provided by anotherembodiment of the invention which is preferably also suitable as an1×EV-DV reverse link solution. The reverse link is described in detailbelow with reference to FIGS. 17 to 23. The reverse link design ispreferably similar to that now standardized in 1×RTT for example butwith some refinements. This allows for a significant reuse of existinghardware and software, while at the same time providing excellent dataperformance.

[0061] Preferably, for all embodiments, a 20 ms physical layer framelength is used for both the reverse link and the forward link. This isconsistent with 1×RTT. Advantageously, this frame size would allow atri-mode modem capable of supporting IS-95, 1×RTT and 1×EV-DV. Also, inthe discussion which follows, where the terms “voice” or “voice user”are used, this is intended to refer to any low rate users, namely usersrequiring the transmission of voice data per se or to users having adata rate equivalent to the data rate required for voice information,i.e. data users requiring a relatively low data rate.

[0062] An objective of wireless access network Radio Link Protocol (RLP)ARQ schemes is to provide improved radio link quality by implementing aretransmission mechanism for all the services and applications. Theseembodiments of the invention provides a new ARQ mechanism for voiceservices in packet wireless communication systems.

[0063] There are two types of the services which may be provided onetype of service provides for delay-sensitive services, such as voiceservice. The other type of service provides for non-delay-sensitiveservice, such as data services.

[0064] For the voice services, as will be detailed below, a base stationmay send signals to multiple wireless terminals in one slot, eachwireless terminal receiving a packet during the slot. In response tothis, multiple wireless terminals will send an ARQ signal back to thebase station to indicate if they received the packets correctly or not.For high-rate data services, a single user will receive data during agiven slot. Two methods of achieving this are provided.

[0065] Forward Link—Time Division Multiplexed Control Implementation

[0066] Details of a first implementation of forward link 172 of FIG. 1will now be provided with reference to FIGS. 1 to 5. The new forwardlink design allows for the efficient use of resources through the use ofmultiple-user forward link slots The forward link employs a preamblethat allows multi-user packets on the forward link. This results inefficient allocation of forward link slots for voice and data servicefor multiple users.

[0067] The forward link is time multiplexed, with 20 ms framesconsisting of 16 slots with 1.25 ms per slot. Each slot contains 1536chips. Transmission starts from one of the 16 slot boundaries. As willbe described in detail below, each slot will support multiple users.

[0068] The forward link time-multiplexes a forward pilot channel, aforward MAC channel, and forward traffic channel(s)

[0069] The forward pilot channel is transmitted by each sector in eachhalf slot on the forward channel. Each pilot channel transmissionconsists of unmodulated BPSK transmitted as 96 chip bursts every halfslot at full sector power.

[0070] The pilot channel is used for acquisition, synchronization,demodulation, decoding and C/I estimation by all wireless terminals inthe coverage area. By transmitting the pilot burst wise in this fashion,a sufficiently accurate C/I estimation can be obtained for data ratecontrol generation and adaptive modulation and coding. Pilot bursts fromall of the sectors are transmitted at the same time to facilitate C/Iestimation.

[0071] Referring to FIG. 2, shown is where in the slot the pilot burstsare transmitted for two modes, namely an active mode during whichforward link data is being transmitted, generally indicated by 100, andan idle mode during which forward link data is not being transmitted,generally indicated by 102.

[0072] In active mode 100, a slot on the forward link (1.25 ms, 1536chips) comprises a first 304 chip data period 104, a first 32 chip MACchannel slot 106, a 96 chip pilot burst 108, a second 32 chip MACchannel slot 110, second and third 304 chip data periods 112, 114, athird 32 chip MAC channel slot 116, a second 96 chip pilot burst 118, afourth 32 chip MAC channel slot 120, and a fourth 304 chip data period122. In the inactive mode 102, the MAC channel slots 106, 110, 116, 120and pilot bursts 108, 118 are transmitted at the same time during theslot as was the case for the active mode, with the no data transmissionduring the data periods.

[0073] The forward MAC channel carries a reverse power control (RPC)channel and a reverse activity (RA) channel.

[0074] The forward traffic channel is provided over the four dataperiods 104, 112, 114, 122, and is used to provide for differentservices with various QoS attributes, such as real time data, non-realtime data, etc. In some slots, one or more cf these data periods 104,112, 114, 122 are used to transmit a preamble which identifies whichusers are being scheduled during the slot.

[0075] Referring again to FIG. 2, the data periods 104, 112, 114, 122are used for a time division multiplexed forward traffic channel, thetime division multiplexing occurring between data transmission, andpilot and MAC channel slot transmission. Advantageously, this allows ahigher number of users per slot with modest rate requirements, or amodest number of high-rate voice and data users.

[0076] During the data periods 104, 112, 114, 122, a number of CDMAWalsh covers are used to transmit forward traffic channels. Preferably,16 16-ary Walsh covers are used. The Walsh covers are allocatable on aper slot basis such that a single slot is adapted to serve multiple lowdata rate or voice users so as to provide efficiency and flexibility,and up to one high data rate user.

[0077] Each slot is either a multi-user slot, or a single high-rate userslot. For a single user slot, all 16 Walsh covers are used to transmitdata to the single high-rate user. In a multi-user slot, the 16 Walshcovers are allocated between up to 16 users, with one, two or four Walshcovers per user.

[0078] Each multi-user slot has a preamble which identifies the userswho are being scheduled during the slot. Single user packets may betransmitted over multiple slots, and the first of such multiple slotscontains a preamble identifying the data user and transmissionparameters for the data packet.

[0079] The base station schedules data packets onto the forward trafficchannel based on channel estimates fed back over the CHESS channelreceived from wireless terminals on the reverse link, QoS requirementsand traffic load at the base station. The base station must schedule atleast one voice frame onto the forward traffic channel for eachsimultaneous voice and data user within one 20 ms frame. The actual ratefor a single user slot is specified by an EDRI (explicit data rateindicator).

[0080]FIG. 3 illustrates an example slot scheduling breakdown for amulti-user slot 960 and a single user transmission 962 composed of twoslots 964, 966. All three slots 960, 964, 966 have the a pair ofrespective pilot periods, and four respective MAC channel slots.Multi-user slot 960 has a multi-user preamble 968 which in this exampleidentifies (through user index construct, described below) four voiceusers each occupying 4 Walsh codes. The transmissions for the four voiceusers are indicated as V1, V2, V3 and V4, For the single usertransmission, the first slot 964 contains a preamble 970 whichidentifies (through the group ID construct) the data user. The entiretraffic capacity of the slot 964 and the following slot 966 is dedicatedto the single user as indicated by D1 in both slots.

[0081] It is to be understood that other field sizes may alternativelybe employed for the MAC channel slots, pilot and data periods. Anotherexample is shown in FIG. 4 for both active and idle modes where in a1536 chip slot, there are be two 348 chip data periods 140, 144, two 72chip pilot bursts 142, 150, two 64 chip MAC channel slots 148, 152, andtwo 284 chip data periods 146, 154.

[0082] The forward channel structure is shown in FIG. 1B. The forwardtraffic or control channel inputs C, D, the preamble and ERDI inputs E,F, the power control and RA channel inputs G, H and the pilot channelinputs K, L are input to TDM (time division multiplexing) block 800which performs time division multiplexing as shown in FIG. 2 forexample. Quadrature spreading is performed at block 802. I and Q outputsare baseband filtered 804, 806, modulated at 810, 812 and then summedtogether at 814 to produce a forward modulated waveform.

[0083] The forward voice traffic channel structure is shown in FIG. 1C.A voice user may be assigned more than one Walsh cover, and preferablyone, two or four Walsh covers. A voice user input is channel encoded830, with an 8K or 13K encoder for example. Then scrambling, sequencerepetition and/or symbol puncturing is performed at 832. Next, QPSK or16 QAM modulation is performed 834. Walsh cover is applied 836 and Walshchannel gain applied 838. Finally, the outputs thus produced for all thevoice users are summed with Walsh Chip level summer 840. Outputs C and Dare inputs to the forward channel structure of FIG. 1B.

[0084] The forward single user data traffic channel structure is shownin FIG. 1D. Forward data traffic channel physical layer packets areencoded with R=1/3 or 1/5 rate encoder 860. A scrambler 862 sequence isadded at 863. Then channel interleaving is employed 864 and modulationis performed by QPSK/8PSK or 16 QAM modulator 866. Symbol repetitionand/or symbol puncturing is performed at 868. Symbol demultiplexing 16to 1 occurs at 870. Then the appropriate Walsh cover is applied for eachof the sixteen channels at 872, Walsh channel gain applied at 873, andWalsh chip level summing occurs at 874. Outputs C and D are inputs tothe forward channel structure of FIG. 1B.

[0085] The preamble channel structure is shown in FIG. 1E. The preambleinitially consists of all 0's. This is signal mapped at 880. Then, a 32symbol bi-orthogonal cover with user index/Group ID i is applied at 882.Sequence repetition is performed at 884, and a preamble gain applied at886. For the EDRI, 8-ary orthogonal modulation is applied at 888, signalmapping occurs at 890, sequence repetition occurs at 892, and an EDRIchannel gain applied at 894. Outputs E and F are inputs to the forwardchannel structure of FIG. 1B. The EDRI indicates the coding andmodulation employed for the single high-rate user.

[0086] There are 32 Walsh×2(plus, minus) possible bi-orthogonal codeswhich may be applied to the preamble structure above, thereby allowingthe identification of 64 different user index/Group ID.

[0087] The preamble channel structure used in multi-user slots is shownin FIG. 1E, but no EDRI is required.

[0088] Each data user has a single Group ID for their data service (thisbeing analogous to user index I), and this is transmitted during thepreamble of a single user slot as indicated above in the discussion ofFIG. 1B. Each voice user has three Group IDs, one GID1 for use when itsvoice is transmitted using one 16-ary Walsh cover, one GID2 for use whenits voice is transmitted using two 16-ary Walsh covers, and one GID4 foruse when its voice is transmitted using four 16-ary Walsh covers. Eachuser has Walsh covers assigned to it for each of the its three GroupIDs, i.e. for GID1 the user is assigned one Walsh cover, for GID2 theuser is assigned two Walsh covers, and for GID4 the user is assignedfour Walsh covers. Multiple users may be assigned the same GIDS. When agiven GID1 is transmitted, then all voice users having been assignedGID1 will know to expect a voice packet on the single Walsh coverassociated with GID1 Similarly, when a given GID2 is transmitted, thenall voice users having been assigned GID2 will know to expect a voicepacket on the two Walsh covers associated with GID2, and when a givenGID4 is transmitted, then all voice users having been assigned GID4 willknow to expect a voice packet on the four Walsh covers associated withGID4. The preamble functions as a user identification channel, allowingusers to determine whether a given slot contains any content for them.

[0089] The structure of the MAC channel slots 106, 110, 116, 120 isdesigned to facilitate this denser and more flexible packing of usersdown to the sub-slot level. The structure of the MAC channel which isused to carry reverse power control commands and reverse activitycommands is shown at FIG. 1F. RPC bits for user ID i are signal mapped900. Then RPC Walsh channel gain is applied at 902. A 64-ary Walsh coveris applied at 904. RA bits, 1 per 8×RABLength slots (100/RABLength bps)are input to bit repetition block 908 with repetition factor equal toRABLength. Then, signal point mapping occurs at 910 and an RA channelgain is applied at 912. A 64-ary Walsh cover is applied at 914. Theoutputs of 904 and 914 are summed with Walsh chip level summer 906 whichhas an output which is sequence repeated 916. Outputs G and H are inputsto the forward channel structure of FIG. 1B. The MAC channel providesone PC bit per slot for up to 63 users and one RA bit per slot. A firststate of the RA bit indicates to all users transmitting on the reverselink that things are fine as they stand, and a second state of the RAbit indicates to all users transmitting on the reverse link that thereis too much activity on the reverse link and that data rates should belowered.

[0090] Finally, the pilot channel structure is shown in FIG. 1G. Here,the pilot channel bits which consist of all 0's, are signal mapped at930 and then the Walsh cover 0 is applied at 932. Outputs K and L areinputs to the forward channel structure of FIG. 1B.

[0091] The forward link physical layer parameters for data are shown inFIG. 5A. Data packets can be from 1 to 16 slots in length the preamblefor the different possibilities also varies from being as small as 128chips to as large as 1024 chips. When the preamble is longer, the userindex/group ID for the data user is repeated.

[0092] The forward link physical layer parameters for voice are shown inFIGS. 5B, 5C and 5D for users having high, medium and low channelestimates respectively. In FIG. 5B, the parameters are used when thereare 16 voice users, with one Walsh code per user. FIG. 5C shows theparameters used when there are eight users with two Walsh codes peruser, FIG. 5D shows the parameters used when there are four users withfour Walsh codes per user.

[0093] Forward Link—Code Division Multiplexed Control Implementation

[0094] Another embodiment of the invention provides a forward linkdesign in which control is multiplexed with data using codemultiplexing. This embodiment will now be described with reference toFIGS. 6 to 16. The new channel breakdown for the forward link is shownin FIG. 6. The forward channels include:

[0095] Forward Pilot Channel (F-PICH) 250;

[0096] Forward Sync Channel (F-SYCH) 252;

[0097] TDPICH channel 254;

[0098] Supplemental Paging Channel (F-SPCH) 258;

[0099] Quick Paging Channel 1 256;

[0100] Quick Paging Channel 2 257;

[0101] Forward Paging Channel (F-PCH) 260;

[0102] User identification channel (UICH) 262;

[0103] Forward Shared Power Control Channel (F-SHPCCH);

[0104] Common Explicit Data Rate Indication Channel (CEDRICH) 266; and

[0105] Shared Channel (SHCH) 268.

[0106] Preferably, the pilot channel 250, sync channel 252, TDPICHchannel 254, quick paging channels 256, 257, and paging channel 260 havethe same channel structure as the corresponding channels as defined byIS2000A. Furthermore, preferably, the shared power control channel 264has a similar structure to the CPCCH (common power control channel)provided by IS2000A, with differences noted below. Each of the channelswhich are not based on IS2000A are described in detail below.

[0107] Forward Link Operation

[0108] The forward link uses code division multiplexing within timedivision multiplexing on a new shared channel (SHCH). The SHCH allowsflexible slot scheduling and slots with multiple voice users and up toone data user. Forward link transmission is organized as 20 ms frames.Each frame consists of sixteen 1.25 ms slots. Each slot contains 1536chips.

[0109] The slot structure of the forward link depends upon whetherservice is to be provided to legacy IS95/1×RTT users. A forwardslot/code structure is shown in FIG. 7 for the case where it is assumedthere are no IS95/1×RTT users. Effectively, there are 16 Walsh length 16code space subchannels.

[0110] The slot structure contains the following channels: Forward PilotChannel (F-PICH) 250 having a Walsh length of 64 chips, Forward SynchChannel (F-SYCH) 252 having a Walsh length of 64 chips, the TDPICHchannel 254 having a Walsh length of 128 chips, the supplemental pagingchannel F-SPCH 258 having a Walsh length of 128 chips. The slotstructure has quick paging channels 256, 257 each having a Walsh lengthof 128. Channels 250, 252, 254, 256, 257 and 258 collectivelyeffectively occupy one Walsh 16 code space. The slot structure also hasForward Paging Channel (F-PCH) 260 having a Walsh length of 64 chips,and eight user identification channel (UICH) 262 each having 8subchannels and Walsh code of length 512 chips, for a total of 64 UICHstubchannels. If additional user identification channel capacity isrequired, then additional Walsh codes can be assigned code spacepermitting. Space may also be taken from the shared channel itnecessary. The slot structure further includes three Forward SharedPower Control Channels (F-SHPCCH) 264 each having 24 subchannels and aWalsh length of 128 chips, giving a total of 72 power control bits perslot capacity since for each of the three code channels, 24 powercontrol bits can be time division multiplexed and transmitted.Preferably, two of the power control bits are used by the ReverseActivity (RA) channel, which are used to broadcast reverse activitycommands and can be used for reverse link rate control. It is noted thatsix bits of the FSPCCH are preferably used for the advanced accesschannel described in applicant's copending application. If additionalpower control subchannels are required, then extra code space may beallocated for this purpose. The slot structure also has a commonexplicit data rate indication channel (CEDRICH) 266 which has four Walshcodes of length 512 chips. Channels 260, 262, 264 and 266 collectivelyeffectively occupy one Walsh 16 code space. Finally, the shared channel(SHCH) 14 which occupies 14 Walsh 16 code spaces. A detailed examplebreakdown of the Walsh separation is provided in the table of FIG. 9.

[0111] In the event there are IS95/1×RTT (legacy) users which need to besupported, the slot structure of FIG. 7 easily adapts to allow this. Asubset of the capacity of the shared channel 268 can be used for theselegacy users. An example is shown in FIG. 8 for the case where it isassumed there are IS95/1×RTT users. The slot structure is the same asthat of FIG. 7 down until the shared channel. The slot structure of FIG.8 has two 1×RTT voice channels 270, 272 each having a Walsh length of128, one 1×RTT data channel 272 having a Walsh length of 32, and oneIS95 voice channel 276 having a Walsh length of 64, these legacychannels collectively occupying one Walsh 16 code space which was takenfrom the capacity formerly allocated to the shared channel leaving asmaller Shared Channel (SHCH) 278 is which occupies 13 Walsh code spacesrather than 14 as was the case for the Shared Channel of FIG. 7.Depending on the number of legacy users at a given time, the size of theshared channel 278 can shrink, potentially down to zero, or grow back tothe maximum 14 Walsh code spaces nominally allocated.

[0112] Forward link Shared Channel (SHCH)

[0113] The shared channel 268 is a very flexible channel. The sharedchannel, in this example, may have up to 14 16-ary Walsh codes.

[0114] In one embodiment, each SHCH 1.25 ms slot is assignable on a TDMbasis for a combination of voice users plus a single data user, or for asingle high-rate data user.

[0115] The assumption being made is that the high-rate data user doesnot require real time traffic delivery. For a given user, it isacceptable to wait until enough information has built up to fill anentire slot for the user and/or to wait until the channel to the givenuser is good.

[0116] In one embodiment, the SHCH has a fixed bandwidth. In anotherembodiment, the SHCH has a bandwidth equal to a maximum bandwidth minusa bandwidth required to service legacy voice and low-rate data users.More specifically, in this embodiment space on the shared channel 268can be taken as needed to support legacy voice and data channels,thereby reducing the size of the shared channel 268.

[0117] Nominally, the shared channel is scheduled on a 1.25 ms basis.However, for high rate data users, longer scheduling periods of 1.25,2.5 and 5 msec may be allowed.

[0118] A data-only SHCH slot has all 14 available 16-ary Walsh codesallocated to a single user's data. Alternatively, if some of the SHCH16-ary Walsh codes have been allocated for legacy traffic, then adata-only SHCH preferably uses all the remaining SHCH 16-ary Walshcodes.

[0119] A hybrid SHCH slot has the 14 available 16-ary Walsh codes (orwhatever number are available after servicing legacy users) splitbetween one or more voice users and up to one data user. Voice users maytake up all of the SHCH 16-ary Walsh codes.

[0120] A number of different modulation and coding schemes arepreferably supported for voice users as summarized in FIG. 12 includingfull, half, quarter and eighth rate. Full rate voice uses Turbo codingand can use either one or two SHCH 16-ary Walsh codes depending upon thechannel estimates (CHE) fed back to the base station and other factors.Half, quarter and eighth rate voice uses convolutional coding and usesonly one SHCH 16-ary Walsh code. The wireless terminal must blindlydistinguish between the five possibilities based on getting the correctCRC. Per voice user gain is also adjusted based on the CHE.

[0121] A number of different modulation and coding schemes are alsosupported for the high rate data user as summarized in the tables ofFIGS. 13 and 14. Other rates may also be supported Data users adaptmodulation and coding based on the Channel Estimate (CHE) every 1.25msec. Because the size of the portion of the shared channel which may bededicated to a high-rate user varies as a function of how many voice andlegacy users are also scheduled in the same slot, many differenteffective data rates are required.

[0122] A preferred forward shared channel structure for a singlehigh-rate data user which is the same as that for a single full ratevoice user is shown in FIG. 10 where it is assumed that the user has NWalsh codes. The single high-rate data user may have up to all N=14Walsh codes, while the voice user will have either one or two Walshcodes. Physical layer packets are encoded with 1/5 rate Turbo encoder402 and then pass through channel interleaver 404 and preferablyprocessed by SPIRSS block 405 and then modulated with modulator 406(which may be QPSK, 8-PSK or 16-QAM depending upon modulation type) Thesymbols thus produced are 1 to N demuxed 416 and the appropriate longcode is added, the long code being produced by applying the long codemask to a long code generator 410 followed by decimator 412. Walshchannel gain is applied 420, and the appropriate N Walsh covers 418 areapplied. Finally Walsh chip level summing 422 occurs.

[0123] In one embodiment of the invention, the even second timingreferenced to UTC (Universal Coordinated Time) is used to select theportion of the 1/5 rate Turbo coded binary symbols to be transmittedover a given slot. Before describing this embodiment in detail, thefollowing notations are defined:

[0124] N is the user payload packet size in number of symbols;

[0125] M is the coded packet size, which is the packed size (in numberof symbols) after 1/5 rate Turbo coding, M=5N;

[0126] L is the actual transmitted packet size in number of symbols. Theeffective coding rate is N/L.

[0127] In both the access network and the wireless terminal, there is acount referenced to the even second. At the start of each even second,the count is cleared to zero. Then for each tour slots (i.e. every 5ms), the count is increased by one. Since there are 1600 slots in oneeven second period, the count value can go from 0 to 399. For example,if the starting position of the even second is aligned with the startingposition of slot 0 of the current frame, the count value at slot 0, 1,2, and 3 of the current frame would be 0. The count value at slot 4, 5,6, and 7 of the current frame would be 1. The count value at slot 8, 9,10, and 11 of the current frame would be 2. The count value at slot 12,13, 14, and 15 of the current frame would be 3. The count value at slot0, 1, 2, and 3 of the next frame would be 3 and so on.

[0128] The Turbo coded packet can be viewed as a periodic signal withthe period equal to M. The actual transmitted packet will be selectedfrom the periodic coded packet based on the count value at the currentslot on which it will be scheduled on. If the packet to be transmittedrequires more than one slot, it will be selected from the periodic codedpacket based on the count value at the first slot.

[0129] Suppose that the count value at the current slot is k. Thestarting position of the actual transmitted packet is calculated from

i 1=1+(kL) modulo M.

[0130] The ending position of the actual transmitted packet iscalculated from

i 2=i 1+L−1

[0131] When the wireless terminal receives the packet, it can derive thepacket size information (N, M, L) from the CEDRIC channel (described indetail below). From the count value at the slot the packet is received(or at the first slot the packet is received if the received packetcontains multiple slots), it knows which portion of the 1/5 rate Turbocoded data packet the received packet belongs to and decodes the packetin a proper way. It the decoded result does not pass CRC, the wirelessterminal will check if the previous received packet is decoded corrector not. If the previous received packet is wrong, the current receivedpacket will be used for soft combining and/or incremental redundancywith the previous received packet. If the previous received packet iscorrect or the joint decoded result is wrong, a NAK signal is sent tothe base station. The current received packet will be stored and may beused for soft combining and/or incremental redundancy with the futurereceived packet.

[0132] A preferred forward shared channel structure for non-full ratevoice is shown in FIG. 11. There is a channel structure instantiationfor each non-full rate voice user. In FIG. 11, two such identicalchannels structure are shown 440, 445. Channel structure 440 will bedescribed by way of example. Physical layer pacxets are encoded withencoder 450 and then pass through channel interleaver 452, and QPSKmodulator 454. I and Q channels thus produced then undergo sequencerepetition and/or symbol puncturing 456. The appropriate long code isadded, the long code being produced by applying the long code mask to along code generator 458 followed by decimator 460. The appropriate Walshcover 462 is applied, Walsh channel gain 464 is applied, and finallyWalsh chip level summing 482 occurs,

[0133] SHCH and Hybrid SHCH slots are scheduled by the base station, andwireless terminals are informed of whether a given slot containsvoice/data for it using the User Identifier Channels (UICH).

[0134] A user identification channel (UICH) is a forward channel whichprovides a method of informing a wireless terminal of whether a currentslot of the shared data channel contains his/her data. In a preferredembodiment, eight Walsh codes of length 512 are allocated for the UICHchannel. A user's identification transmitted on this channel consists ofa three bit sub-identifier transmitted using an I or Q component of oneof the eight Walsh codes. There are four different three bitsub-identifiers as follows:

[0135] Identifier 1: 000

[0136] Identifier 2: 010

[0137] Identifier 3: 110

[0138] Identifier 4: 101

[0139] In each slot, a sub-identifier is spread by a 512-ary Walsh codeand can be transmitted on either I or Q components. Since I and Qcomponents can be detected independently and eight Walsh codes are usedfor the UICH, there is a total of 64 users (8 Walsh codes×2 components×4sub-identifiers) which can be identified uniquely by the channel. Foreach slot, up to sixteen users can be identified. The UICH channelstructure is shown in FIG. 15. The mapping between a given user and aUICH identifier is set up each time a wireless terminal connects. Then,the sub-identifiers to be transmitted on the I and Q components areencoded with encoders 320, 322, provided with channel gain with channelgain elements 324, 326, and then Walsh code covered (not shown) andtransmitted.

[0140] The above described User Identifier Channels (UICH) indicatewhich user or users are scheduled in the current slot. Up to sixteenusers may be identified per slot. A user with simultaneous Data andVoice has one UICH for Data and one UICH for Voice. The user is informedof its UICH(s) when during initial signaling with the base station.

[0141] More generally, the sub-identifier is an N bit identifier, andthe Walsh code is one of P M-ary Walsh codes. The user identificationchannel is transmitted in K chip slots, and has I and Q channels,thereby providing the 2*K/(M) bit capacity, and the ability to transmit2*K*M/N user identifiers per slot. In the above example, M=512, K=1536,N=3 and P=8 thereby providing the ability to transmit 16 useridentifiers per slot, and the ability to uniquely identify 64 differentusers. In another specific example, M=512, K=1536, N=3, P=16 therebyproviding the ability to transmit 32 user identifiers per slot, and theability to uniquely identify 128 different users.

[0142] Preferably, voice users are scheduled in the first half frame(i.e. in the first eight slots). An ACK signal is sent, by a wirelessterminal if the wireless terminal receives a voice packet correctly.When the wireless terminal decodes the UICH correctly and detects thesignal by measuring its energy and the CRC of the received voice packetfails, a NAK signal is sent to the base station. Otherwise, no ACK orNAK signal will be sent. When a NAK is received for a voice packet, thebase station will re-transmit the packet unless the voice rate is 1/8rate in which case the voice packet is not retransmitted.

[0143] Voice users are assigned a voice channel number (V=0, 1, 2, . . .) which is used to calculate the one or two W16 codes on which it willreceive voice information. The supplemental paging channel SPCHbroadcasts the total number of 16-ary Walsh codes available (Nd) on theSHCH. For Data only SHCH slots, Nd will be the number of codes availableto the data user. Also broadcast is the number of 16-ary Walsh codesavailable for voice in hybrid SHCH slots (Nv). In a hybrid slot, therewould be Nd-Nv Walsh codes for the high rate data user. The W×116 andW×216 codes for a particular voice user are calculated by:

X 1=15−mod(V, Nv) and X 2=15−mod(V+1, Nv)

[0144] Scheduling is performed on the basis of QoS commitments, thechannel estimates received from the wireless terminals and sector selectvalues. If a sector select erasure is received corresponding to a datauser then no data will be scheduled for that user. If a sector selecterasure is received corresponding to a voice user then voice informationwill continue to be scheduled for that user. Two sector select valuescorresponding to another valid sector must be received before the activesector stops sending voice information.

[0145] A preferred structure for the SPCH is shown in FIG. 16. TheSupplemental Paging Channel (SPCH) broadcasts Nd and Nv as detailedabove. The channel bits containing this information are convolutionallyencoded with encoder 430, and interleaved with channel interleaver 432.A long code mask generated by long code mask generator 434 and decimator436 is applied, and then channel gain 438 and demux functions 440 areperformed.

[0146] The Common Explicit Data Rate Indication Channel (CEDRICH) isused to indicate the coding/modulation format applied for data only useof the shared channel. Another embodiment of the invention provides thischannel used to determine the data rate for data transmitted on theShared Channel. Preferably, four Walsh codes of length 512 are used forthe channel.

[0147] The data rate can be determined from the number of Walsh codesused for data, the data packet size and packet length. The SupplementalPaging Channel broadcasts the number of Walsh codes for the SharedChannel and the number of Walsh codes used for voice when both voice anddata are transmitted in the Shared Channel in a single slot. The CEDRICchannel carries the information of packet size, packet length and a slottype flag indicating whether the slot is for one data-only user or formultiple data and voice users. To help wireless terminals to do highorder demodulation (64-QAM or 16-QAM), a gain value may be included inCEDRIC.

[0148] The CEDRIC is composed of three sub-channels. The first one(CEDRIC_a) carries the packet length in units of slots, and it isrepresented by three symbols (1536 chips after spreading) transmitted inI component of a Walsh code in a slot. The mapping between the symbolsand packet length is specified in Table 2. TABLE 2 The mapping betweenthe symbols and packet length Packet Length (slots) Symbols 1 No energy2 000 4 111

[0149] The second sub-channel (CEDRIC_b) carries information consistingof Data Packet Size and slot type flag for Low Order Modulation (QPSKand 8-PSK), The third sub-channel (CEDRIC_c) carries informationconsisting of Data Packet Size and slot type flag and the gain value forhigh order modulation (64-QAM or 16-QAM).

[0150] Each sub-channel uses different Walsh codes. For low ordermodulations, one Walsh code is assigned to carry the packet sizeinformation. Two packet sizes will be used if the packet is transmittedin one slot, therefore only one bit is needed to indicate the packetsize (see Table 3). One more bit (slot type flag) is needed to indicatewhether the slot is for one data-only user or for multiple data andvoice users (see Table 4). Four packet sizes can be used when a packetis transmitted in multiple slots and two bits are needed to indicate thepacket size (see Table 5). However, only data packets are transmitted inmultiple slots and thus the slot type flag is not needed. In summary,for both single slot packets or multiple slot packets, two bits areencoded into six symbols, which are spread by a 512-ary Walsh code andtransmitted on I and Q components. TABLE 3 Packet Size Indication forSingle Slot Packets Packet Size Packet Flag Size 0 3072 1 1536

[0151] TABLE 4 Slot Type Indication for Single Slot Packets Slot TypeFlag Slot Type 0 Data only 1 Mixed

[0152] TABLE 5 Packet Size Indication for Multiple Slot Packets PacketSize Packet Flag Size 00 3072 01 1536 10  768 11  384

[0153] For high order modulations, two and a half Walsh codes (halfmeaning the Q component of the Walsh code used for packet length) areassigned to carry the packet size and the gain information. Similar tothe low order modulation, a 1-bit packet size flag and a 1-bit slot typeflag are used for single slot packets while a 2-bit packet size flag isused for multiple slot packets. Five bits are used to represent thegain. All seven bits are encoded into fifteen symbols and are spread by512-ary Walsh codes.

[0154] If a packet is transmitted in a single slot, the packet size,slot type flag (and gain when applicable) will be transmitted in thesame slot with the data packet. If a packet is transmitted in multipleslots, the packet length (number of slots) will be transmitted in thefirst slot. The packet size (and gain when applicable) will betransmitted in the following slots. Effectively, only one sub-channel istransmitted in one slot.

[0155] Shared Power Control Channels (SHPCCH) handle reverse link PCwhen forward link uses SHCH. Details of a preferred implementation areprovided in Applicants below-referenced copending application.

[0156] The SHPCCH is used by the reverse advanced Access Channel (AACH).Predefined PC bits from the SHPCCH to acknowledge and to power controlwireless terminal pilots prior to message transmission from wirelessterminals during access probes.

[0157] Preferably, two bits are used to send a single reverse activity(RA) control bit repeated twice. A first state of the RA bit indicatesto all users transmitting on the reverse link that things are fine asthey stand, and a second state of the RA bit indicates to all userstransmitting on the reverse link that there is too much activity on thereverse link and that data rates should be lowered.

[0158] NAK for Outer Loop Power Control

[0159] The base station adjusts the power transmitted to users on thebasis of the channel estimate information fed back from the wirelessterminals. Preferably, in another embodiment, NAK signals fed back fromwireless terminals are used to determine a measure of frame error rate,and this measure is used for outer loop power control, i.e. to changethe manner by which the channel estimates are mapped to base stationtransmission power. By counting the NAK and no ACK/NAK frames, the basestation can calculate the forward link frame error rate. This error ratecan then be used to make a decision in respect of outer loop powercontrol. No other signaling from the reverse link is needed for thisouter loop power control.

[0160] Reverse Link Operation

[0161] Details of a reverse link design provided by another embodimentof the invention used for reverse links 174, 176 of FIG. 1 will now beprovided with reference to FIGS. 17 to 23. Preferably, the reverse linkis the 1×RTT reverse link with the addition of a new channel for feedingback channel estimates and sector selections, new channels for ARQfeedback and reverse rate indication, and a modified reversesupplementary channel having the data rate indicated by the Reverse RateIndication (RRI) channel. Each 20 ms reverse link frame consists of 161.25 ms slots or power control groups. Code channels are used formultiplexing (fundamental, supplemental channels). A frame offset isapplied to randomize the reverse link transmissions.

[0162] Referring now to FIG. 17A, the reverse lint has the followingchannels:

[0163] a reverse pilot channel (R-PICH) 272;

[0164] reverse MAC channels consisting of the R-CHESS (reverse channelestimate and sector select) channel 270, RRI (reverse rate indicator)channel 282, reverse data ARQ (R-DARQ) channel 276, reverse voice ARQ(R-VARQ) channel 274;

[0165] reverse traffic channels which include reverse fundamentalchannel (R-FCH) 278 (for voice traffic) and reverse supplemental channel(R-SCH) 280 (for data traffic);

[0166] reverse advanced access channel (R-AACH) 288;

[0167] reverse dedicated control channel (R-DCCH) 284; and

[0168] reverse common control channel (RCCCH) 286.

[0169] Each of the reverse link channels will now be detailed in turnwith reference to FIG. 20 which is a reverse link timing diagram showinghow the timing of the various reverse link channels relates to that ofthe forward channels slots as received by a wireless terminal. Forwardlink traffic is transmitted over 20 ms frames containing 16 1.25 msforward channel slots 190. T0 is the frame boundary at the wirelessterminal with an assumed round trip delay of 0. Of course there would bea non-zero round trip delay which would increase as a function of awireless terminal's distance from the base station. This would have theeffect of delaying all of the reverse link timing with respect to theactual forward link slot timing, but not with respect to the forwardlink slots as received at a given wireless terminal.

[0170] Reverse Pilot Channel, RRI Channel, and VARQ Channel

[0171] The reverse link MAC is composed collectively of the fast reverseVARQ channel 274, reverse DARQ channel 276, RRI channel 282 and R-CHESSchannel 270 (described in detail below). The structure of the pilotchannel is preferably the same as the 1×RTT reverse link pilot channel.The last 384 chips of every 1.25 msec slot contains a single bit ofinformation. For 1×RTT this bit is a power control bit. For thisembodiment of the invention this bit is instead used to communicate VARQand RRI. The pilot channel is used by the BS as a phase reference, forchannel estimation and for the reverse link power control.

[0172] The reverse pilot channel 194 is the same as the 1×RTT reversepilot channel when operating in backward compatible mode. In backwardscompatible mode, the wireless terminal is a legacy wireless terminal. Inthis embodiment of the invention, rather than providing anotherdedicated ARQ channel for VARQ for each wireless terminal, the powercontrol bits (PCB) of the pilot signals in the 1×RTT reverse linkstructure are replaced by a reverse rate indicator (RRI) and ARQ forvoice services. When the wireless terminal used the forward sharedchannel for the forward link, then each pilot channel 194 slot containspilot, RRI, and VARQ fields as described in detail below. The timing ofthe reverse pilot channel is shown in FIG. 20 and is slightly differentdepending on whether voice only indicated generally at 194, or voice anddata is being transmitted indicated generally at 202. In both cases, thereverse pilot channel 194, 202 is aligned with the forward channelslots, so there are 16 1.25 ms slots.

[0173] The reverse link pilot channel is summarized at a very high levelin FIG. 19. Again, this is similar to the 1×RTT reverse pilot channelexcept that the power control bits are now replaced by RRI (reverse rateindicator) and Voice ARQ (VARQ) bits. The pilot channel over one slotcontains a pilot period 180 during which 1152 pilot chips are sent, anda period 182 during which the PCB/RRI/VARQ is sent over 384 chips, PCBbeing sent by legacy terminals During an entire frame, there are 16 bitpositions available through the collective use of period 182 from 16slots (formerly used for power control) which are now used for RRI/VARQ.

[0174] Case 1: Voice Only Users

[0175] For the voice only users, the position of the ACK or NAK bit isnot fixed. Slots 2, 6, 10 and 14 are reserved for RRI. A single RRI bitis mapped to all 4 bit positions to indicate the use of the fundamentalchannel and dedicated control channel. Setting all four RRI bits to “0”in one frame indicates that there is only fundamental channel beingtransmitted. Setting all four bits in one frame to “1” indicates thatthe DCCH and fundamental channel are being transmitted.

[0176] If a user's voice data is decoded correctly, the ACK VARQ signalwill be sent to the base station in all the slots in the frame. Ifnothing was transmitted for the user in a given slot, or if the user'svoice data is decoded incorrectly, then a NAK VARQ signal will be sentto the base station. Preferably, a “1” is sent to indicate an ACK, and a“0” is sent to indicate a NAK. The possible positions of the VARQsignals are in slots 3, 4, 7, 8, 9, 11, 12, 13 and 15 of the currentframe and slots 0 and 1 of the next frame. For a Forward traffic channelvoice frame transmitted in slot n of the forward channel, thecorresponding ACK channel bit is transmitted in slots n+2 and anyfollowing remaining slots in the frame and slots 0 and 1 of thefollowing frame.

[0177] An example of this can be seen in the timing diagram of FIG. 20where it is assumed a forward voice packet for a voice only user is sentto a given wireless terminal during slot n 204. After slot n and slotn+1 are received, slot n+2 containing an RRI bit 208, the VARQ isincluded in the RRI/VARQ bit in the reverse pilot channel 194 during thefollowing the remaining non-RRI slots of the frame, including forexample slots 206, 207 and during the first two slots of the next frame(not shown).

[0178] Case 2: Voice and Data users

[0179] The timing of the VARQ for voice plus data users is shown in FIG.20 indicated generally at 202. In this case, 14 PC bits in one framewill be used for RRI to indicate the rate being used on the reversesupplemental channel. Preferably, each RRI symbol (3 bits) is mapped toa simplex code with a length of seven, repeated twice, mapped toRPI/VARQ locations 0 to 8 and 11-16. The RRI is used to indicate whetherthe dedicated control channel or supplemental channel or neither isactive for the current frame. The three bit RRI symbol can take one ofeight values, one value (preferably 0) indicating that there is no DCCHand no supplemental channel, one value (preferably 1) indicating thatthe DCCH only is being transmitted, and remaining values 2 through 7indicating supplemental channel only, and indicating a particular ratefor the supplemental channel. The rates are detailed below under thediscussion of the supplemental channel with reference to FIGS. 22 and23.

[0180] The VARQ signals are transmitted in fixed positions at the 9thand 10th slots 203, 205. If the user's data is correctly decoded, theACK VARQ signal will be sent. Otherwise, a NAK VARQ signal will be sentto base station.

[0181] Data ARQ

[0182] For data ARQ, the data ARQ channel 196 is used by data or voiceand data users which is also aligned with the forward channel slots, sothere are 16 1.25 ms slots. An ACK signal is sent to the base station ifthe wireless terminal receives a data packet correctly. When thewireless terminal detects the proper UICH and the CRC of the receiveddata packet fails, a NAK signal is sent to the base station. When thewireless terminal does not detect the proper UICH then no ACK or NAKsignal will be sent. The DARQ signals for data are sent using the DARQchannel in the first half slot starting two slots after the end of thedata packet is received at the wireless terminal. An example of this isshown in FIG. 20 where a data packet has been transmitted on slot n, andthe DARQ 197 is sent on the R-DARQ channel 196 in the first half slot ofslot n+3.

[0183] The structure of the reverse DARQ channel is shown in FIG. 18.DARQ takes one bit per slot in first ½ slot, employs bit repetition 600,signal point mapping 602 and Walsh cover 604.

[0184] Reverse Link Supplemental Channel and Fundamental Channel

[0185] The reverse supplemental channel has a variable data rate from4.8 kbps to 1228.8 kbps. The fundamental channel is supported for voice,with preferably both 1×RTT 8k and 13k vocoders being supported as wellas a new 8k vocoder with turbo coded full rate voice. Simultaneous voiceand data can be transmitted, The variable data rates are determined bythe wireless terminal in cooperation with the base station through theuse of a rate set identifier broadcast by base station on the forwardlink, and a RRI (reverse rate indicator) sent on the reverse link asdiscussed in detail above. The rate set identifies either the low rateset or the high rate set. Signaling is transmitted on the dedicatedcontrol channel,

[0186]FIG. 22 is a table of an example set of reverse traffic channelcoding and modulation parameters for a low rate set (one supplementalchannel), and FIG. 23 is a table of an example set of reverse trafficchannel coding and modulation parameters for a high rate set (twosupplemental channels). Parameters are shown for seven different sets ofparameters, each set of parameters being distinguished by a differentreverse rate indicator. Each set of parameters has a respective datarate, encoder packet size, overall code rate, code symbols/Packet, codesymbol rate, interleaved packet repeats, mod. Symbol rate, datamodulation, and PN chips per encoder bit. Reverse rate indicator 0 meansthat there is no dedicated control or supplemental channel content.Reverse rate indicator 1 means that only the dedicated control channelis being used on the reverse link. Rate indicators 2 through 7 relate tosupplemental channel content. In the event a user is also transmittingvoice, this would be transmitted on the fundamental channel.

[0187] R-CHESS Channel

[0188] A channel estimate and sector selector reporting scheme forwireless air interface is provided by an embodiment of the invention. Inthis scheme, by time division multiplexing channel estimate and sectorselector information (compared to sending the informationsimultaneously), the bit rate is reduced significantly and reverse linkcapacity is improved. A handoff mechanism is also provided which usesthe sector selector and channel estimate information.

[0189] In the new scheme, channel conditions are reported in anobjective manner. A wireless terminal may report its channel estimate toa base station to help the base station to determine the datatransmission rate. A wireless terminal may also monitor all the sectorsit can receive, and select the best one and report it. With the channelestimate and sector selector information, base stations can use goodchannel conditions more efficiently and improve forward link throughput.In the new reporting scheme, in every eight consecutive time slots,wireless terminals report channel estimates in the seven consecutiveslots and report sector selector information in one slot.

[0190] The new channel is referred to herein as the R-CHESS channel,standing for Reverse Channel Estimate and Sector Selector (R-CHESS)channel. The structure of the R-CHESS channel is shown in FIG. 17B.Three bits are used to represent a channel estimate or a change inchannel estimate 300, and three bits are used to represent sectorselector symbols 302. The channel estimate or change in the channelestimate is mapped to the three bit CHE or Δ-CHE value depending on thecoding scheme of the channel estimate. CHE represents the currentchannel estimate, while Δ-CHE represents the difference between thecurrent channel estimate and the previous channel estimate. These aretime division multiplexed 304 such that seven channel estimates 300 (CHEand/or Δ-CHE) are reported for every one sector selection 302. Themultiplexed stream is then simplex encoded with encoder 306. Thecodeword is then repeated 14 times and punctured as indicated by block308. The result is signal point mapped 310, and then spread by theR-CHESS channel Walsh cover 312.

[0191] The CHE (delta CHE), SS valuer are transmitted at a data rate of800 values per second. The timing of the CHESS channel relative to otherreverse link channels is shown in the timing diagram of FIG. 20. TheR-CHESS channel 192 is shown to have 1.25 ms slots which are one halfslot offset from the forward channels slots. In this manner, evenallowing for round trip delay, a given R-CHESS channel slot is receivedat the base station in time for the base station to use the CHEinformation for the next forward channel slot. In the illustratedexample, in a 16 slot frame, the SS is transmitted during slots 0 (SS1)and 8 (SS2), CHE is transmitted during slots 1, 3, 5, 7, 9, 11, 13 and15, and Δ-CHE is transmitted during slots 2, 4, 6, 10, 12, 14. Inanother embodiment, a CHE value is sent slots 1 to 7 and 9 to 16 and noΔ-CHE is sent.

[0192] A handoff mechanism using the R-CHESS information will now bebriefly described. The sector selector indicator is used to indicate thesector that the wireless terminal thinks it should be operating. Thethree bit field can indicate one of seven sectors and a null value. As abackground process, the wireless terminal measures the pilot signalstrength of base station sectors, and when the signal strength of asector of a base station becomes sufficiently strong, this is reportedto the access network, and the sector is added to the active set for thewireless terminal. A sector select value is defined for each sector inthe active set. Similarly, when a sector's pilot strength goes below athreshold, that sector is removed from the active set.

[0193] For reverse traffic, all sectors in the active set listen totransmissions from the wireless terminal, and preferably, for eachreceive slot, the best of multiple signals received by multiple sectorsis selected as the receive signal. This provides a soft reverse linkhandoff mechanism

[0194] For forward traffic, only the sector defined by the sector selectvalue transmits subject to the timing constraints below. This can changefrom slot to slot. Thus, forward link handoff is completely sectorselect driven.

[0195] Preferably, for data or data/voice users, the sector select valueis not allowed to change from one sector value directly to anothersector value. It can only change from a sector value to the null valuethen to a sector value.

[0196] If the sector select value changes from a sector value (forexample, sector A) to the null value, the wireless terminal stillreports CHE values for sector A for the some fixed number of slots, forexample 7. Then the sector select can change to a different sector valueand the wireless terminal starts to report CHE for the new sector. Forsimultaneous voice and data users, both voice and data are handed off atthe same time.

[0197] For voice only users, preferably the sector select is allowed tochange directly from one sector value to another sector value. Also ifsector select changes a sector value, (e.g. A to B) then the wirelessterminal continues to report CHE for sector A for the remainder of theframe, the assumption being that voice users get one slot per frame.Then the wireless terminal begins reporting values for B.

[0198] Advanced Access Channel

[0199] A new advanced access channel described in applicant's copendingapplication number [attorney docket 71493-980] filed the same day asthis application and hereby incorporated by reference in its entiretyimproves reverse link capacity.

[0200] An example reverse channel I and Q mapping is shown in FIG. 21A.Inputs to this are the R-CHESS channel input B, the pilot/RRI/VARQchannel input B, DARQ channel input C, fundamental channel input D, andsupplemental channel or dedicated control channel or enhanced accesschannel or common control channel input E.

[0201] The structure of the advanced access channel shown in FIG. 21B.The advanced access channel or common control channel bits are added toa frame quality indicator 700, turbo encoded 702, symbol repeated insymbol repetition 704, punctured with symbol puncture 706, and thenblock interleaved with block interleaver 708. Signal point mapping isperformed 710 and then the appropriate Walsh cover applied 712.

[0202] A similar structure is employed for the fundamental channel,supplemental channel or dedicated control channel bits as indicated atFIG. 21C. The channel bits are added to a frame quality indicator 720,turbo encoded 722, symbol repeated in symbol repetition 724, puncturedwith symbol puncture 726, and then block interleaved with blockinterleaver 728. Signal point mapping is performed 730, 732 and then theappropriate Walsh cover applied 734, 736 with a different Walsh coverbeing applied tot he reverse supplemental or dedicated control channelthan to the reverse fundamental channel.

[0203] Numerous modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described herein.

We claim:
 1. A method of transmitting over a forward link in a CDMA(code division multiple access) communications system, the methodcomprising: transmitting forward link frames, each frame comprising aplurality of slots; for each slot, transmitting a forward sharedchannel, the forward shared channel being adapted to have up to apredetermined maximum number of Walsh covers, and the forward sharedchannel being scheduled slot-wise to carry in some slots content for asingle high-rate data user, in some slots content for a plurality ofvoice users (a voice user being voice or low-rate data); transmitting auser identification channel adapted to allow users to determine whichslots contain their content.
 2. A method according to claim 1 whereinthe forward shared channel is further adapted to have scheduled in someslots content for a plurality of voice users and a single high-rate datausers.
 3. A method according to claim 2 wherein the user identificationchannel is transmitted in parallel with the shared channel using adifferent code space.
 4. A method according to claim 3 wherein duringeach slot the forward shared channel is scheduled over a number of Walshcovers equal to the predetermined maximum number of Walsh covers minus anumber of Walsh covers necessary to accommodate legacy users beingserviced during the slot.
 5. A method according to claim 4 wherein thepredetermined maximum number of Walsh covers is 14 16-ary Walsh covers.6. A method according to claim 3 wherein the Walsh covers are 16-aryWalsh covers and in a given slot, one or more of the 16-ary Walsh coversis further sub-divided for the plurality of voice users, with allremaining 16-ary Walsh covers of the forward shared channel beingassigned to a shared data channel which is made available to a singlehigh-rate data user at a time.
 7. A method according to claim 6 whereineach slot has a 1.25 ms slot duration, with the shared data channelcontent for a given user may occupy multiple contiguous slots.
 8. Amethod according to claim 7 further comprising transmitting controlinformation in respect of the shared data channel.
 9. A method accordingto claim 8 wherein the control information in respect of the shared datachannel comprises an indication of a number of contiguous slots to bemade available to a given data user.
 10. A method according to claim 9wherein the control information comprises a data packet size andsingle/hybrid slot indicator for low order modulation (QPSK and 8-PSK)and data packet size, single/hybrid slot indicator, and gain value for64QAM and 16QAM shared channel data for high order modulation.
 11. Amethod according to claim 3 wherein at least some of the slots containvoice transmitted at full rate.
 12. A method according to claim 11further comprising turbo encoding the voice to be transmitted at fullrate and transmitting such content using one or two shared channel16-ary Walsh codes.
 13. A method according to claim 3 wherein at leastsome of the slots contain voice content transmitted using half, quarteror eighth rate.
 14. A method according to claim 11 further comprisingencoding half, quarter and eighth rate voice channels usingconvolutional coding and transmitting such content using only one sharedchannel 16-ary Walsh code.
 15. A method according to claim 3 whereinframes have a 20 ms duration, with each frame consisting of sixteen 1.25ms slots, and each slot containing 1536 chips.
 16. A method according toclaim 3 wherein the user identification channel is used to inform aparticular user whether a current slot of the shared data channelcontains data for the user by transmitting a user identifier comprisinga Walsh code and a sub-identifier.
 17. A method according to claim 16wherein the sub-identifier is an N bit identifier, and the Walsh code isone of P M-ary Walsh codes.
 18. A method according to claim 17 whereinthe user identification channel is transmitted in K chip slots, and hasI and Q channels, thereby providing the 2*K/(M) bit capacity, and theability to transmit 2*K*M/N user identifiers per slot.
 19. A methodaccording to claim 16 wherein M=512, K=1536, N=3 and P=16 therebyproviding the ability to transmit 32 user identifiers per slot, and theability to uniquely identify 128 different users.
 20. A method accordingto claim 16 wherein M=512, K=1536, N=3 and P=8 thereby providing theability to transmit 16 user identifiers per slot, and the ability touniquely identify 64 different users.
 21. A method according to claim 15wherein a voice only user is assigned a single user identifier, and auser with voice and data is assigned one user identifier for data andone user identifier for voice.
 22. A method according to claim 1 whereinfor a given slot during which high-rate data is to be transmitted, datais transmitted for a high-rate data user likely to have good channelconditions during the slot.
 23. A method according to claim 22 furthercomprising performing adaptive modulation and coding for the shared datachannel based on channel estimates fed back every slot.
 24. A methodaccording to claim 3 further comprising coding voice content in one offive possible ways depending upon rate and channel estimate as follows:full rate voice uses Turbo coding and can use either one or two sharedchannel 16-ary-Walsh codes with 8PSK modulation with one shared channel16-ary Walsh code or QPSK modulation with two shared channel 16-aryWalsh codes; half, quarter and eighth rate voice uses convolutionalcoding and uses only one shared channel 16-ary Walsh code.
 25. A methodaccording to claim 1 further adapted to schedule voice users by: givingpreference to schedule voice users in a first half frame; for each slot,looking for an ACK or NAK VARQ signal from each voice user scheduledduring the slot and where possible rescheduling in the second half framevoice users from which a NAK VARQ signal is received.
 26. A methodaccording to claim 25 wherein the VARQ signals are received on a1×RTT-like reverse pilot channel in place of predetermined former powercontrol bit locations.
 27. A method according to claim 26 whereinreverse rate indicator (RRI) signals are also received on the1×RTTT-like reverse pilot channel in place of predetermined former powercontrol bit locations.
 28. A method according to claim 27 wherein eachframe has 16 slots and the positions of the VARQ and RRI signals obeythe following rules: for users with voice service only, the VARQ validbit positions are in slots 3, 4, 7, 8, 9, 11, 12, 13 and 15 of a currentframe and slots 0 and 1 of a following frame, and slots 2, 6, 10 and 14are reserved for the RRI; for a user with both data and voice services,the RRI is transmitted in slots 0 to 8 and 11 to 15 and the VARQ istransmitted in slots 9 and
 10. 29. A method according to claim 28wherein if a user's voice data in a given slot is decoded correctly, theACK VARQ signal will be sent to the base station in all the slots in theframe following the given slot and in the first two slots of a followingframe, and if no voice was transmitted for the user in a given slot, orif the user's voice data is decoded incorrectly, then a NAK VARQ signalwill be sent on all slots until a slot containing the user's voice datais correctly decoded.
 30. A method according to claim 1 furthercomprising: processing a reverse channel for each voice user scheduledduring a given slot, and looking for a NAK VARQ signal or an ACK VARQsignal in predetermined slot positions in the reverse channel relativeto the given slot.
 31. A method according to claim 1 further comprisingtransmitting a forward supplemental paging channel, the forwardsupplemental paging channel broadcasting a number of 16-ary Walsh codesavailable for shared channel slots and a number of 16-ary Walsh codesavailable for voice in hybrid shared channel slots.
 32. A methodaccording to claim 1 further receiving channel estimates from each user.33. A method according to claim 32 wherein for each user, adaptivemodulation and coding is performed on the basis of the channel estimatesreceived for that user, and scheduling of users in each slot is alsoperformed on the basis of the channel estimates.
 34. A method accordingto claim 33 further comprising receiving sector select values from eachuser.
 35. A method according to claim 34 wherein the channel estimatesand sector select values are received on a Channel Estimate and SectorSelector (R-CHESS) channel from each user.
 36. A method according toclaim 35 wherein the sector select value for a given user identifies abest sector for the given user and handoffs are performed for the givenuser on the basis of the sector selector values received from that user.37. A method according to claim 36 wherein: each sector selector valueis used to indicate the sector that the wireless terminal thinks itshould be operating; each sector select value indicates a sectorbelonging to an active set, the active set being sectors previouslyidentified to have an acceptable signal strength; for reverse linktraffic, all sectors in the active set listen to transmissions from thewireless terminal with a best of multiple signals received by multiplesectors being selected as the receive signal thereby providing a softreverse link handoff mechanism; for forward link traffic, only thesector defined by the sector select value for a given user transmits tothe given user.
 38. A method according to claim 36 wherein for data ordata/voice users, the sector select value is not allowed to change fromone sector value directly to another sector value, the sector selectvalue only being allowed to change from a sector value to the null valuethen to a sector value, and wherein for voice only users, the sectorselect value is allowed to change directly from one sector value toanother sector value.
 39. A method according to 32 wherein sectorselection precludes the changing from a sector value directly to anothersector value, only allowing a change from a sector value to a null valuethen to another sector value.
 40. A method according to claim 35 furthercomprising: in the event a sector select erasure is received in acurrent active sector, if the sector select erasure is receivedcorresponding to a data user then no data will be scheduled for thatuser, and the sector select erasure is received corresponding to a voiceuser then voice content will continue to be scheduled for that user. 41.A method according to claim 38 further comprising: requiring two sectorselect values corresponding to another valid sector to be receivedbefore the current active sector stops sending voice content.
 42. Amethod according to claim 1 further comprising providing systematicpredetermined incremental redundancy symbol selection for voice and dataon the shared channel by: using an even second timing referenced to UTC(Universal Coordinated Time) to select a portion of turbo coded datasymbols to be sent in a given slot; using a count value k which startson each even second which counts from k=0 to Kmax incrementing every(even second interval)/K; calculating a starting (i1) and ending (i2)symbol positions of a actual Turbo transmitted packet are fromi1=1+mod(kL,M), i2=i1+L−1, the Turbo coded packet being viewed as aperiodic signal with period M, where N is the user payload packet sizein number of symbols, M is the coded packet size, which is the packedsize (in number of symbols) after Turbo coding, and L is the actualtransmitted packet size in number of symbols resulting in an effectivecoding rate would be N/L; a wireless terminal deriving packet sizeinformation, and using the count value, determining which portion of theturbo coded packet the received packet belongs to.
 43. A methodaccording to claim 3 further comprising assigning voice Walsh codes by:assigning each voice user a voice channel number V (V=0, 1, 2 . . . )which is used to calculate the one or two 16-ary Walsh codes on whichthe voice user will receive voice information; using a supplementalpaging channel (SPCH) to broadcast the number of 16-ary Walsh codesavailable for data only shared channel slots (Nd) and the number of16-ary Walsh codes available for Voice in Hybrid shared channel slots(Nv); calculating the two Walsh codes for a particular user, W×116 andW×216 according to X1=15−mod(V,Nv) and X2=15−mod(V+1, NV).
 44. A methodaccording to claim 1 further comprising: transmitting a given user'svoice content using a Walsh cover previously made known to the givenuser.
 45. A method according to claim 30 further comprising usingnegative acknowledgment (NAK) and acknowledgement (ACK) signals forouter loop power control in voice and data transmissions.
 46. A methodaccording to claim 45 wherein the outer loop power control comprises:calculating a forward link frame error rate by counting a number of NAKand no ACK/NAK frames; and determining outer loop power control basedupon said forward link frame error rate.
 47. A method according to claim1 further comprising explicitly indicating a data rate for the sharedchannel by: providing an explicit data rate sub-channel indicatingpacket size, packet length and a slot type flag indicating whether theslot is for one data-only user or for a data user and one or more voiceusers.
 48. A method according to claim 1 wherein: each slot comprises aplurality of pre-defined data transmission periods during which dataand/or voice can be transmitted only, has at least one pre-definedperiod during which pilot data is transmitted only, and at least onepre-defined period during which MAC channel is transmitted only.
 49. Amethod according to claim 48 adapted to transmit multi-user slots, eachmulti-user slot having a preamble containing said user identificationchannel, and to one slot and multi-slot single user high-ratetransmissions, each first slot of a single user high-rate transmissionhaving a preamble containing said user identification channel.
 50. Amethod according to claim 49 wherein the forward pilot channel istransmitted by each sector in each half slot on the forward channel asunmodulated BPSK.
 51. A method according to claim 49 wherein the pilotchannel is transmitted as 96 chip bursts every half slot at full sectorpower.
 52. A method according to claim 49 wherein each slot comprises afirst 304 chip data period, a first 32 chip MAC channel slot, a 96 chippilot burst, a second 32 chip MAC channel slot, second and third 304chip data periods, a third 32 chip MAC channel slot, a second 96 chippilot burst, a fourth 32 chip MAC channel slot, and a fourth 304 chipdata period.
 53. A method according to claim 52 wherein the MAC channelis used to transmit forward power control commands and reverse activitycommands.
 54. A method according to claim 52 wherein: each voice user isassigned at least one group ID; each data user is assigned a group ID; asingle group ID is transmitted on the preamble, so as to inform anyuser(s) having been assigned that group ID that the slot has content forthe user.
 55. A method according to claim 54 wherein: each voice userhas three Group IDs, one GID1 for use when its voice is transmittedusing one 16-ary Walsh cover, one GID2 for use when its voice istransmitted using two 16-ary Walsh covers, and one GID4 for use when itsvoice is transmitted using four 16-ary Walsh covers; wherein each userhas Walsh covers assigned to it for each of the its three Group IDs suchthat when a given group ID is transmitted, then all voice users havingbeen assigned the given group ID will know the slot contains theircontent, will know how many Walsh codes recover and which Walsh codes torecover.
 56. A method according to claim 1 adapted to transmit datausing parameters from any row of the table in FIG. 5A.
 57. A methodaccording to claim 1 adapted to transmit voice using parameters from anyrow of the table in FIG. 5B.
 58. A method according to claim 1 adaptedto transmit voice using parameters from any row of the table in FIG. 5C.59. A method according to claim 1 adapted to transmit voice usingparameters from any row of the table in FIG. 5D.
 60. A method accordingto claim 2 adapted to transmit voice using parameters from any row ofthe table in FIG.
 12. 61. A method according to claim 2 adapted totransmit data using parameters from any row of the table in FIG.
 13. 62.A method according to claim 2 adapted to transmit data using parametersfrom any row of the table in FIG.
 14. 63. A method of informing aparticular user whether a current slot of a shared data channel containsdata for the user, the method comprising: providing a useridentification channel; transmitting a user identifier comprising aWalsh code and a sub-identifier.
 64. A method according to claim 63wherein the sub-identifier is an N bit identifier, and the Walsh code isone of P M-ary Walsh codes.
 65. A method according to claim 64 whereinthe user identification channel is transmitted in K chip slots, and hasI and Q channels, thereby providing a 2*K/(M) bit capacity, and anability to transmit 2*K*M/N user identifiers per slot.
 66. A methodaccording to claim 65 wherein M=512, K=1536, N=3 and P=16 therebyproviding an ability to transmit 32 user identifiers per slot, and anability to uniquely identify 128 different users.
 67. A method accordingto claim 65 wherein M=512, K=1536, N=3 and P=8 thereby providing anability to transmit 16 user identifiers per slot, and an ability touniquely identify 64 different users.
 68. A method according to claim 63wherein a voice only user is assigned a single user identifier, and auser with voice and data is assigned one user identifier for data andone user identifier for voice.
 69. A method according to claim 63wherein for a given slot during which high-rate data is to betransmitted, data is transmitted for a high-rate data user likely tohave good channel conditions during the slot.
 70. A method according toclaim 63 further comprising performing adaptive modulation and codingfor high rate data users based on channel estimates fed back every slot.71. A method of assigning voice Walsh codes comprising: assigning eachvoice user a voice channel number V (V=0, 1, 2 . . . ) which is used tocalculate one or two 16-ary Walsh codes on which it will receive voiceinformation; using a Supplemental Paging Channel (SPCH) to broadcast thenumber of 16-ary Walsh codes available for Data only shared channelslots (Nd) and the number of 16-ary Walsh codes available for Voice inHybrid shared channel slots (Nv); calculating the two Walsh codes for aparticular user, W×116 and W×216 according to X1=15−mod(V,Nv) andX2=15−mod(V+1,Nv).
 72. A wireless terminal adapted to function in a CDMAcommunications system, the terminal comprising: a receiver adapted toreceive frames having a slot structure in which there is a useridentification channel and a shared channel, the shared channel havingbeen transmitted using a plurality of Walsh codes, and containingcontent for either a plurality of voice users, a plurality of voiceusers and one high-rate data user, or only one high-rate data user; thewireless terminal being adapted to decode the user identificationchannel to determine if a current slot of the shared channel containsvoice and/or high-rate data content for the wireless terminal (voicecontent being voice or low-rate data).
 73. A wireless terminal accordingto claim 72 wherein in the event the wireless terminal determines thecurrent slot contains voice content for the wireless terminal, thereceiver is adapted to blindly distinguishing between a plurality ofdifferent coding and modulation types which may have been used totransmit the voice content based on getting a correct CRC.
 74. Awireless terminal according to claim 72 adapted to decode the useridentifier channel using an assigned user identifier Walsh andsub-identifier.
 75. A wireless terminal according to claim 72 adapted tobe assigned at least one group ID as a voice user and adapted to beassigned a group ID as a data user; wherein a single group ID istransmitted on a preamble of each slot, so as to inform the wirelessterminal whether that the slot has content for the user.
 76. A wirelessterminal according to claim 75 wherein each voice user has three GroupIDs, one GID1 for use when its voice is transmitted using one 16-aryWalsh cover, one GID2 for use when its voice is transmitted using two16-ary Walsh covers, and one GID4 for use when its voice is transmittedusing four 16-ary Walsh covers; wherein each user has Walsh coversassigned to it for each of the its three Group IDs such that when agiven group ID is transmitted, then all voice users having been assignedthe given group ID will know the slot contains their content, will knowhow many Walsh codes recover and which Walsh codes to recover.
 77. Awireless terminal according to claim 70 further adapted to perform fastARQ for voice.
 78. A wireless terminal according to claim 72 adapted toperform fast ARQ for voice by: determining a correlation result based onthe user identifier channel; if the correlation result is greater than afirst threshold and less than a second threshold, the wireless terminaldecoding further channels, and if these channels pass an integritycheck, sending an ACK to the base station, and otherwise, the wirelessterminal discarding the current packet; if the correlation result isgreater than the second threshold, the wireless terminal decodingfurther channels, and if these channels pass an integrity check, sendinga ACK signal to the base station, and if these channels do not pass theintegrity check sending an NAK to the base station.
 79. A wirelessterminal according to claim 78 further adapted to save current packetraw data samples for soft combining or incremental redundancy with thefuture received data packet.
 80. A wireless terminal according to claim72 further adapted to look for a single user identifier if the terminalis expecting voice only, and if the terminal is expecting voice anddata, to look for two user identifiers, one for voice and one for data.81. A wireless terminal according to claim 80 further comprising: in theevent a current slot contains data for the wireless terminal asdetermined by the user identification channel, decoding another forwardlink channel to determine parameters used in transmitting the datapacket, and then using a data rate determined from the another forwardlink channel to demodulate the data on the shared channel.
 82. Awireless terminal according to claim 72 further adapted to perform voiceARQ.
 83. A wireless terminal according to claim 82 adapted to performvoice ARQ using a 1×RTT-like pilot channel.
 84. A wireless terminalaccording to claim 83 wherein the 1×RTT-like pilot channel is furtherused to transmit a RRI (reverse rate indicator).
 85. A wireless terminalaccording to claim 84 adapted to perform voice ARQ by transmitting VARQbits subject to: when functioning with a voice service only, the VARQvalid bit positions are in slots 3, 4, 7, 8, 9, 11, 12, 13 and 15 of acurrent frame and slots 0 and 1 of a next frame, with slots 2, 6, 10 and14 being reserved for RRI (reverse rate indicator); when functioning inwith both data and voice services, the position for the VARQ is fixedwithin a frame at slots 9 and 10, with remaining slots used for reverserate indicator.
 86. A wireless terminal according to claim 82 adaptedto: when functioning as a wireless terminal of a mixed data and voiceuser, map each RRI (reverse rate indicator) symbol (3 bits) to a simplexcode with length of 7 repeated twice and mapped to slots 0-8 and 11-15,with voice ARQ being one bit mapped into slot 9 and 10, the RRI beingused to indicate whether the Reverse Dedicated Control Channel orReverse Supplemental Channel or neither is active for the current frame;when functioning as a wireless terminal of a voice only users, map theRRI bit to slots 2, 6, 10 and 12, with the voice ARQ being one bitmapped into any two consecutive slots that are not reserved for RRI. 87.A wireless terminal according to claim 82 further adapted to transmit aChannel Estimate and Sector Selector (R-CHESS) channel having a slot foreach forward slot, with some slots containing channel estimates andother slots containing sector select values.
 88. A wireless terminalaccording to claim 87 wherein the CHESS channel is adapted to allowsector selection for data users which precludes the changing from asector value directly to another sector value, only allowing a changefrom a sector value to a null value and then to another sector value.89. A wireless terminal according to claim 88 wherein if the sectorselect value changes from a first sector value to a null value, thewireless terminal is adapted to continue to report channel estimates forthe first sector value for a number of subsequent slots; when the sectorselect value changes to a different sector value, the wireless terminalstarts to report channel estimates for this new sector.
 90. A wirelessterminal according to claim 87 wherein each channel estimate comprises athree bit value representative of an absolute channel estimate.
 91. Awireless terminal according to claim 87 wherein the channel estimatescomprise three bit values alternating between being representative of anabsolute channel estimate and a change in channel estimate.
 92. Awireless terminal according to claim 87 wherein: sector select valuesare sent during the first and ninth of sixteen available CHESS channelslots, and channel estimates are sent during the remaining of the slots.93. A wireless terminal according to claim 72 adapted to process packetssent on a shared channel providing systematic predetermined incrementalredundancy symbol selection for voice and data in which an even secondtiming referenced to UTC (Universal Coordinated Time) has been used toselect a portion of turbo coded data symbols to be sent in a given slot,a count value k is used which starts on each even second which countsfrom k=0 to Kmax incrementing every (even second interval)/K; starting(i1) and ending (i2) symbol positions are calculated of a actual Turbotransmitted packet are from i1=1+mod(kL,M), i2=i1+L−1, the Turbo codedpacket being viewed as a periodic signal with period M, where N is theuser payload packet size in number of symbols, M is the coded packetsize, which is the packed size (in number of symbols) after Turbocoding, and L is the actual transmitted packet size in number of symbolsresulting in an effective coding rate would be N/L, the wirelessterminal being adapted to process the packets by: deriving packet sizeinformation, and using the count value, determining which portion of theturbo coded packet the received packet belongs to.
 94. A wirelessterminal according to claim 93 further adapted to decode the packet andperforming a quality check on decoded packet; if the decoded result doesnot pass the quality check, check if the previous received packet wasdecoded correct or not; if the previous received packet is wrong, thecurrent received packet will be used for soft combining and/orincremental redundancy with the previous received packet; if theprevious received packet is correct or the joint decoded result iswrong, a NAK signal is sent to the base station, and the currentreceived packet will be stored and may be used for soft combining and/orincremental redundancy with the future received packet.
 95. A wirelessterminal according to claim 72 adapted to transmit supplementarychannel(s) according to parameters in any row of the tables in FIG. 22and FIG.
 23. 96. A method for time division multiplexing of reversesupplemental channel and reverse control channel, said methodcomprising: multiplexing said a supplemental channel and a controlchannel; indicating, via a reverse rate indicator (RRI), whether asupplemental channel or a control channel or neither is active; whereinsaid method enables sharing of channels by physical resources inwireless terminal modems and base station modems.